CN101111989A

CN101111989A - Electronic system for a field device that is fed by an external electric energy supply

Info

Publication number: CN101111989A
Application number: CN200580047442.0A
Authority: CN
Inventors: 罗伯特·拉拉
Original assignee: Endress and Hauser Flowtec AG
Current assignee: Endress and Hauser Flowtec AG
Priority date: 2004-12-29
Filing date: 2005-12-16
Publication date: 2008-01-23
Anticipated expiration: 2025-12-16
Also published as: DE102004063735A1; CN101111989B

Abstract

The system has two voltage controllers providing constantly controlled internal useful voltages at a preset voltage level. A third voltage controller is provided, through which partial current of supply current flows for setting and maintaining an internal input voltage of the system at the voltage level. The useful currents that are driven respectively by the useful voltages flow through an operating and evaluation circuit (50). An independent claim is also included for a field device comprising an electronic system.

Description

Field apparatus electronic system by external power source

Technical field

The present invention relates to a kind of by the field apparatus electronic system that is used for field apparatus of external power source and field apparatus with this field apparatus electronic system.

Background technology

In the industrial process measuring technique, particularly also link together with the process automation of chemistry or technology and/or the control of industrial equipment, for simulation or digital measurement value signal in local generative process parameter, the measuring instrument that has also adopted the process of closing on to install is called as field apparatus.Same field apparatus can constitute one or more change procedure parameter and therefore and the adjusting instrument of influence process.For example for respectively with detected and with controlled procedure parameter, can draw by prior art, can be for introducing or the corresponding container of packing into, the liquid in conduit or the silo for example, the mass flow of Powdered, vaporous or vaporous medium, density, viscosity, material level or limit position, pressure, temperature or identical.The example that extends by this class, by field apparatus well known to those skilled in the art by describing in detail below with reference to document, i.e. WO-A03/048874, WO-A02/45045, WO-A02/103327, WO-A02/086426, WO-A01/02816, WO-A00/48157, WO-A00/36379, WO-A00/14485, WO-A95/16897, WO-A88/02853, WO-A88/02476 US-B6799476, US-B6776053, US-B6769301, US-B6577989, US-B6662120, US-B6574515, US-B6535161, US-B6512358, US-B6487507, US-B6480131, US-B6476522, US-B6397683, US-B6352000, US-B6311136, US-B6285094, US-B6269701, US-B6236322, US-A6140940, US-A6014100, US-A6006609, US-A5959372, US-A5796011, US-A5742225, US-A5742225, US-A5687100, US-A5672975, US-A5604685, US-A5535243, US-A5469748, US-A5416723, US-A5363341, US-A5359881, US-A5231884, US-A5207101, US-A5131279, US-A5068592, US-A5065152, US-A5052230, US-A4926340, US-A4850213, US-A4768384, US-A4716770, US-A4656353, US-A4617607, US-A4594584, US-A4574328, US-A4524610, US-A4468971, US-A4317116, US-A4308754, US-A3878725, EP-A1158289, EP-A1147463, EP-A1058093, EP-A984248, EP-A591926, EP-A525920, EP-A415655, DE-A4412388, DE-A3934007.Respectively by external power source, this power supply provides voltage and by this power voltage supply, flows through the electric current of this field apparatus electronic system in field apparatus described above.

When field apparatus is under the situation of measuring instrument, and this measuring instrument comprises corresponding physical electronic or chemical electronic survey sensor in addition, is used for the detection of procedure parameter separately.This transducer is fit into the chamber wall of medium separately at least or guides in the distribution of the guiding of medium separately, and conduit for example, and acting as generates the particularly electronics of the procedure parameter of represent at least one initial acquisition, measuring-signal as far as possible exactly.For the processing of measuring-signal, measuring transducer also is connected at the scene in the equipment electronic system, operation and the analysis circuit handling or analyze especially for the continuation of at least one measuring-signal.In a large amount of such field apparatuss, be used for operating of the drive signal following excitation of the measuring transducer of measuring-signal generation by the generation of timeliness at least of operation and analysis circuit, promptly this transducer directly acts on medium at least or in fact directly acts on medium by corresponding probe in the mode that is fit to measure, with the corresponding reaction of the parameter that causes Yu will detect.Drive signal for example can be about current strength, and magnitude of voltage and/or frequency adjust accordingly.As these effective examples, being about to electrical drive signal in the medium makees the measuring transducer of corresponding conversion and particularly will enumerate and be used for the flow measuring sensor of the measurement of timeliness flow media at least, this transducer has at least one by drive signal excitation, produce the coil in magnetic field or at least one by measuring in the super body wave launcher of drive signal excitation or the container and/or the material level and/or the limit level sensor of monitoring material level, microwave antenna for example, the Gouboun lead, waveguide acoustics or electromagnetic surface wave, the submergence body of vibration or identical.

In order to hold this field apparatus electronic system, described field apparatus comprises the electronic system shell in addition, as described in US-A6397683 or WO-A00/36379, also can connect away from field device configurations by the lead of a flexibility, perhaps for example show, directly be disposed at measuring transducer or be disposed at the measuring transducer shell place that separates with measuring transducer as EP-A903651 or EP-A1008836.The electronic system shell, as EP-A984248, US-A4594584, US-A4716770, US-A6352000 shows, through being usually used in holding some mechanical components of measuring transducer, for example, the distortion or the vibrating body of the mould shape that is out of shape on the operational degree under mechanical influence, rod shape, sleeve-like or tubulose also can in contrast to this paper and begin described US-B6352000.The field apparatus of described type is connected with each other by the data transmission system that is connected in the field apparatus electronic system usually in addition and/or is connected with corresponding process control computer, and field apparatus for example sends measured value signal and/or receives operating data and/or operational order in an identical manner by (4mA to 20mA) current circuit and/or by digital data bus whereby.Here particularly serial, field bus system, PROFIBUS-PA for example, FOUNDATION FIELDBUS and corresponding host-host protocol are as data transmission system.The measured value signal of transmission continue can be handled and be shown in display for example and/or be converted to other operation signal by process control computer, magnet valve for example, electric motor etc. as the field apparatus of regulating the instrument formation as corresponding measurement result.

A large amount of field apparatuss, particularly field measuring instrument of aforementioned forms in addition, being designed to of electronics aspect, they can satisfy the requirement of intrinsic explosive risk itself.These field apparatuss drive with low electronic power accordingly, can not cause electric spark or electric arc under the shortcoming ignition condition.For example European standard EN50 014 and EN50 020 have provided the explosion protection of self-shield, and promptly electronic installation is configured to satisfy " internal security (Ex-i) " ignition protection mode of definition in the standard.According to this protected mode, electric current present in the equipment at the scene, any moment of voltage and electrical power all can not surpass given current limit value, voltage pole limit value and power limit value.These three limiting values are selected as follows, promptly under error situation or the ceiling capacity that discharges owing to short circuit can not produce the spark that can light a fire.Usually the electrical power of the field apparatus of self-shield can not surpass 1W (=watt).Voltage can be by the Z-diode, and electric current for example can be by resistance, and power can be remained on below the prescribed limit value by the combination of pressure limiting and current limiting element.

Modern field apparatus often refers to so-called two-wire field device, and wherein the field apparatus electronic system only also sends the transient measurement value to analytic unit in the external power source and/or that be connected with this external power source electric coupling by this unique two-conductor line by a unique two-conductor line with external power source electrical connection and field apparatus electronic system.This field apparatus electronic system comprises the flow straightener that is flow through by supply current of the adjustment that is used for electric current and/or modulation respectively, clock oscillation especially for supply current, the inside input voltage that is used for the built-in function and the analysis circuit of field apparatus operation and is arranged at the field apparatus electronic system of dividing by supply power voltage, in-line power circuit for built-in function and analysis circuit power supply, this in-line power circuit comprises the voltage regulator that at least one is flow through by the variable shunting of supply current, the interior inside effective voltage of field apparatus electronic system that this voltage regulator provides substantial constant to adjust to preset level.The example of two-wire field device, particularly two-wire system measuring instrument or two-wire system are regulated instrument like this, can be by WO-A03/048874, WO-A02/45045, WO-A02/103327, WO-A00/48157, WO-A00/26739, WO-A94/20940, US-B6799476, US-B6577989, US-B6662120, US-B6574515, US-B6535161, US-B6512358, US-B6480131, US-B6311136, US-B6285094, US-B6269701, US-A6140940, US-A6014100, US-A5959372, US-A5742225, US-A5672975, US-A5535243, US-A5416723, US-A5207101, US-A5068592, US-A5065152, US-A4926340, US-A4656353, US-A4317116, EP-A1147841, EP-A1058093, EP-A591926, EP-A525920, EP-A415655, DE-A4412388, DE-A3934007 learns.

Because historical reasons, these two-wire field device major parts are designed to, adjust to a value between 4mA and the 20mA (milliampere), the transient current intensity of the instantaneous supply current that flows through has also been represented the transient measurement value that is generated by field apparatus simultaneously or has been sent to the instantaneous adjusted value of field apparatus in the unique two-conductor line that constitutes current circuit.Therefore in such two-wire field device, there is a special problem, nominally in fact the electrical power (hereinafter to be referred as " but govern power ") that promptly can be transformed at least or will be transformed by the field apparatus electronic system can fluctuate in the mode that can not meet during operation in wide region.Such result is exactly, modern two-wire field device (2L-field apparatus), the modern two-wire system measuring instrument (2L measuring instrument) that particularly has (4mA to 20mA) current circuit, therefore be typically designed to, the instrumental function that realizes by the microcomputer in analysis and the function circuit is changeable, but and makes most of operation and analysis circuit that transforms less power can adapt to instantaneous govern power thus.

But the proper fit of field apparatus electronic system and govern power, the for example record of US-B6799476 and US-B6512358, but can reach by the power of instantaneous field apparatus conversion and the compensation of instantaneous govern power, and in the following manner, promptly the operation and the individual feature unit of analysis circuit with the clock rate operation of respective change or, but, even can close (standby or park mode) off and on instantaneous govern power value.Design with the two-wire system measuring instrument, have in the field apparatus of measuring transducer of activation, the electrical power that transforms in the instantaneous equipment at the scene, as US-B6799476 and US-A6014100 or WO-A02/103327 demonstration, but can be adapted to instantaneous govern power by the adaptation of the instantaneous electrical power that in measuring transducer, transforms, for example accompany corresponding adjustable gating rate by the clock oscillation of drive signal of buffering in case of necessity, the clock oscillation drive signal with this gating rate, and/or by the maximum current intensity of drive signal and/or reducing of maximum voltage value.

Certainly the instrumental function of the field apparatus of implementing with the two-wire system measuring instrument sexually revises major part and also has following result, be the operation in operation and the accuracy of analysis circuit decision measured value, and/or operation and analysis circuit refresh the regular of measured value for example, but depend on instantaneous govern power, and be subjected to change restriction.The shortcoming that the buffering of the excess power that timeliness exists also can only be corrected the two-wire system measuring instrument with (4mA is to 20mA) current circuit conditionally.On the one hand, because often require same intrinsic explosive risk own for these two-wire system measuring instruments usually, therefore the excess electron energy that whenever exists after all can only be stored in measuring instrument electronic system inside with the degree of very restriction.On the other hand, instantaneous supply current and the excess energy that whenever exists only depend on the transient measurement value, so for low-down lastingly, but the unusual moving measured value of high-amplitude wave on the time, and corresponding energy buffer thus fully can be unloaded through the long time cycle.Thus, for the conversion of the power management of the such complexity in the field apparatus be bother very much and also require circuit and the expensive power measurement of energy, what can contrast is described in WO-A00/26739, US-B6799476, among US-B6512358 and the EP-A1174841.

In addition, more a step has shown that the clock oscillation that is fit to of drive signal and/or the independent member of Operations Analyst circuit are just suitable conditionally to have the aforementioned field apparatus that is used for medium guiding that timeliness at least flows and the measuring transducer of measuring.Particularly begin US-B6799476, US-B6691583, US-A6006609 at this paper, US-A5796011, US-A5687100, US-A5359881, US-A4768384, the application of the measuring transducer of US-A4524610 or the described oscillatory type of WO-A02/103327.Wherein the field apparatus of Xian Shiing is used for measurement, particularly mass flow, density or the viscosity of flow media parameter in the conduit.Purpose thus, corresponding measuring transducer comprises at least one vibration, that be used for boot media in operation measuring tube respectively, a kind of excitation system that is electrically connected with the field apparatus electronic system, this system have the vibratory stimulation mechanical influence measuring tube, that be used for the measuring tube driving, and a kind of sensing system, the on-the-spot measuring-signal of measuring tube vibration of representing generates by the osciducer that at least one is disposed at measuring tube.Not only vibratory stimulation but also osciducer all are preferably electricity-moving type, also all respectively by a magnet exciting coil and one and this coil by magnetic field and interactional movable core constitutes.

Because the amplitude and the frequency adjustment of the drive signal of the high accuracy that the measuring transducer operation is required are necessary for scanning clearly on the time of excitation system measuring tube vibration.Degree also wants to refresh frequently relatively the measured value that provides for the measurement that flow media carries out in the same manner.In addition, the very high mechanical time constant of major part of the oscillatory system that is made of measuring transducer can cause, for the identical acceleration under the various situations, particularly in unsettled starting of oscillation process, need high driving power and/or must apply the long relatively starting of oscillation time.Further experiment shows, because the memory capacity that electrical power limits usually, the buffering of the excess energy in the field apparatus also is difficult to cause the remarkable improvement of the signal to noise ratio that depends on the measuring tube amplitude of oscillation.Therefore for the two-wire system measuring instrument of the measuring transducer with activation of aforementioned forms, particularly be used for the two-wire system measuring instrument directed flow moving medium, the vibration-type measuring transducer for having, temporary transient and the closing of part of operation and analysis circuit also is unaccommodated.

The another kind of possibility of the field apparatus improved efficiency of aforementioned type, particularly for the two-wire system measuring instrument, be, at least adopt for the realization of instrumental function as much as possible on I govern power, the corresponding efficient that is about to field apparatus is optimized in the scope than the I govern power at least.To the campsite, for example accompany for the power supply circuits of field apparatus electronic system in-line power and to be described by US-B6577989 or US-A6140940.Particularly wherein the purpose of solution is, the in fact transformable electrical power in inside is optimized.For this reason, provide respectively in the equipment electronic system at the scene and be used for the inside input voltage adjustment of aforesaid field apparatus electronic system and remain on can input voltage regulation device given, adjustable level in case of necessity, this input voltage regulation device has and acts on the initial pressurizer of field apparatus electronic system, but this pressurizer depends on instantaneous govern power and the instantaneous true power that needs, and is flow through at least off and on by shunting supply current branch, transformable.But aforementioned field apparatus electronic system has following shortcoming, be that the totality load is in fact by identical inside effective voltage power supply and this unique effective voltage collapse under any circumstance, for example as the consequence of low current, all can cause the field apparatus can not normal running or even directly cause the unexpected temporary malfunctioning fully of field apparatus electronic system.

Summary of the invention

The shortcoming of the prior art of being discussed by the example of aforementioned conventional 2L measuring instrument is set out, purpose of the present invention thus is, invent a kind of field apparatus electronic system that is fit to aforementioned field apparatus, this electronic system can make to be analyzed and function circuit, the microprocessor that provides in it particularly, at least at the scene ongoing operation and wherein be selected at least separately functional unit, particularly microprocessor in the normal running of equipment provides the electric energy of enough degree all the time.

Technical solution of the present invention is, the field apparatus electronic system by external power source of field apparatus, the external power source particularly unipolarity and/or the ambipolar variable supply current that particularly unipolar supply power voltage are provided and drive wherein by this supply power voltage, this field apparatus electronic system comprises:

-by the flow straightener that supply current flows through, be used for adjusting and/or modulating the clock of supply current, particularly supply current,

-be used to control the built-in function and the analysis circuit of field apparatus, and

-in-line power circuit, it is applied in from the inner input voltage of the field apparatus electronic system of supply power voltage dividing potential drop and to built-in function and analysis circuit power supply, this in-line power circuit has

--first voltage regulator, it is flow through by particularly variable supply current first at least off and on, this voltage regulator provides the first inner effective voltage in the field apparatus electronic system, adjust to this effective voltage substantial constant can be given first level

--second voltage regulator, it is flow through by particularly variable supply current second at least off and on, and this voltage regulator provides the second inner effective voltage in the field apparatus electronic system, and this effective voltage is variable in voltage range that can be given, and

--pressurizer, it is flow through by particularly variable supply current the 3rd at least off and on, this adjuster be used for the inside input voltage adjustment of field apparatus electronic system and remain to can be given level, particularly variable level in operating process,

-wherein the operation and analysis circuit not only flow through at least off and on but also flow through by the second particularly variable effective current by the first particularly variable effective current, wherein first effective current is driven by first effective voltage, and second effective current is driven by second effective voltage.

The present invention also is to comprise the field apparatus of aforementioned field apparatus electronic system in addition.In first scheme of field apparatus of the present invention, this instrument is used for measuring and/or monitor at least one the given physics and/or the chemical parameters of the medium that pipeline particularly and/or container guide, flow particularly, density, viscosity, material level, pressure, temperature, pH value etc., this measuring instrument also comprises the physics-electronic survey sensor that is electrically connected with the field apparatus electronic system for this reason, and this transducer is made a response for the variation of at least one parameter and provided at least one and the corresponding measuring-signal of this parameter, particularly variable signal voltage and/or variable signal code at least off and on.In the alternative plan of field apparatus of the present invention, this instrument is used for adjusting at least one the given physics and/or the chemical parameters of the medium that pipeline particularly and/or container guide, flow particularly, density, viscosity, material level, pressure, temperature, pH value etc., this measuring instrument also comprises the electronic-physical regulating and controlling element that is electrically connected with the field apparatus electronic system for this reason, this regulating and controlling element with its to adjusting the influential adjustment action of parameter the variation to the control signal of at least one setting react signal voltage that this control signal is particularly variable and/or variable signal code.

According to first structure of the present invention, the inside input voltage of field apparatus electronic system and/or second effective voltage of field apparatus electronic system are depended on the instantaneous voltage height of terminal voltage and are adjusted, and this terminal voltage is from supply power voltage dividing potential drop and equipment electronic system two ends at the scene at first.Improving that the present invention should construct, the inside input voltage of field apparatus electronic system by pressurizer remain on can be given operation particularly on the variable level, this level is lower than terminal voltage.By pressurizer inner input voltage is remained on this level, this level can be in operation particularly stagelyly or variable constantly basically.

According to second structure of the present invention, second effective voltage is depended on the instantaneous voltage height and/or depend on from the instantaneous voltage value of supply power voltage dividing potential drop and the initial terminal voltage at equipment electronic system two ends at the scene of the inside input voltage of field apparatus electronic system and is adjusted.

According to of the present invention the 3rd the structure, second effective voltage depend in three shuntings at least one transient current intensity and adjust.Improving that the present invention should construct, second effective voltage depends on the transient current intensity of the 3rd shunting and adjusts.This external the present invention should construct another improve, second effective voltage depend on the transient current intensity of second shunting and field apparatus electronic system the inside input voltage the instantaneous voltage height and adjust.

According to the 4th structure of the present invention, outside power supply provide have variable, the supply power voltage of Bo Dong voltage height particularly.

According to the 5th structure of the present invention, the supply power voltage that is provided by external power source drives supply current, and the current strength of this supply current is variable, particularly fluctuates in unpredictalbe mode basically.

According to the 6th structure of the present invention, in operation and analysis circuit, provide the memory circuit that is used for temporary transient storage of electrical energy.

According to the 7th structure of the present invention, pressurizer comprises the member, particularly semiconductor element etc. that are mainly used in the dissipation electric energy and derive the heat energy that wherein forms thus.

According to the 8th structure of the present invention, in operation and analysis circuit, provide at least one microprocessor and/or digital signal processor, wherein first effective voltage or by the secondary voltage of its derivation to small part as operating voltage.

According to the 9th structure of the present invention, in operation and analysis circuit, provide at least one amplifier, wherein at least one in two effective voltages or by the secondary voltage of its derivation to small part as operating voltage.

According to the tenth structure of the present invention, in operation and analysis circuit, provide at least one A/D converter, wherein first effective voltage or by the secondary voltage of its derivation to small part as operating voltage.

According to the 11 structure of the present invention, in operation and analysis circuit, provide at least one D/A converter, wherein at least one in two effective voltages or by the secondary voltage of its derivation to small part as operating voltage.

According to the 12 structure of the present invention, the instrument that in operation and analysis circuit, provides the voltage at equipment electronic system two ends at the scene and/or the electric current that flows in the equipment electronic system at the scene and reference value to compare.Improving that the present invention should construct, if operation and analysis circuit detect second effective voltage and be lower than for given minimum effective voltage limiting value of second effective voltage and the 3rd shunting and be lower than for the given minimum diverter pole limit value of the 3rd shunting, then operation and analysis circuit generate the alarm signal of signaling the electricity shortage of field apparatus electronic system at least.During another that should construct in the present invention improves, the field apparatus electronic system comprises the comparator that detection voltage that at least one will be derived by the 3rd shunting of supply current and affiliated reference voltage compare in addition, and/or with second effective voltage and reference voltage compares under at least one comparator.

According to the 13 structure of the present invention, comprise the detection resistance that is used to generate basically with the proportional detection voltage of electric current in addition.

According to the 14 structure of the present invention, comprise in addition and measuring and regulon, be used to detect and be adjusted at the voltage, particularly second effective voltage at field apparatus electronic system two ends, and/or the electric current that flows in the equipment electronic system at the scene, particularly the second and/or the 3rd shunting.Improving that the present invention should construct, measurement and regulon are controlled pressurizer like this, if make that the comparator of second effective voltage and reference voltage comparison under at least one is signaled second effective voltage have been exceeded for the given maximum effective voltage limiting value of second effective voltage, then the 3rd shunting is flowed.During another that should construct in the present invention improves, measure and regulon is adjusted to a given voltage height according to input voltage and/or terminal voltage with the voltage difference that forms between input voltage and the terminal voltage.

According to the 15 structure of the present invention, the field apparatus electronic system only is electrically connected by unique couple of conductor with external power source.

First of the field apparatus structure according to the present invention, this field apparatus at least off and on by data transmission system with away from the external control unit communication of field device configurations, wherein also provide telecommunication circuit in the equipment electronic system at the scene, its control is through the communication of data transmission system.Improving that the present invention should construct, first effective voltage or thus the secondary voltage of dividing potential drop to the operating voltage of small part as telecommunication circuit.

Second structure according to first scheme of field apparatus according to the present invention, the operation of field apparatus electronic system and analysis circuit generate the particularly transient measurement value of numeral of representing the parameter that will measure and/or will monitor at least by at least one measuring-signal at least off and on.Improving that the present invention should construct, flow straightener is adjusted supply current according to the measured value of at least one measurement of instantaneous representative and/or monitoring parameter.During another that should construct in the present invention improved, supply current was that variable direct current and flow straightener are designed at least off and on Modulation and Amplitude Modulation with supply current to measured value.

The 3rd structure according to first scheme of field apparatus according to the present invention, supply current is pulse current at least off and on, and wherein flow straightener provides clock pulse for supply current.

The 4th structure according to first scheme of field apparatus according to the present invention, operation and analysis circuit comprise that at least one is used for the drive circuit of measuring transducer, and second effective voltage or secondary voltage to the small part that derived by this effective voltage are used as operating voltage in this circuit.Improving that the present invention should construct, drive circuit comprises operational amplifier at least.During another that should construct in the present invention improved, drive circuit comprised that at least one D/A converter and/or at least one are used to generate the signal generator of drive signal.That should construct according to the present invention is another perfect, and measuring transducer comprises the particularly variable electrical impedance by drive circuitry, particularly has the magnet exciting coil of variable inductance and/or has the Measurement of capacitor of variable capacitance.The electrical impedance of measuring transducer depends at least one measurement and/or monitoring parameter and changes in addition.In addition, at the signal voltage at the electrical impedance two ends that change and/or the signal code of electrical impedance that flows through variation as measuring-signal.

The 5th structure according to first scheme of field apparatus according to the present invention, operation and analysis circuit comprise at least one A/D converter that is used at least one sensor signal, in this transducer first effective voltage or the secondary effective voltage of deriving by this voltage to small part as operating voltage.Improving that the present invention should construct, operation and analysis circuit comprise the microcomputer that at least one is connected with A/D converter, it particularly constitutes by microprocessor and/or signal processor, is used to generate measured value, and wherein first effective voltage is to the operating voltage of small part as microcomputer.

The 6th structure according to first scheme of field apparatus according to the present invention, measuring transducer comprises that at least one is used for the measuring tube of boot media, it is fit in the conduit, particularly vibration at least off and in operation.Improving that the present invention should construct, disposed at least one magnet exciting coil at the measuring transducer place, be used to generate particularly variable magnetic field.During another that should construct in the present invention improves, the exciting current that magnet exciting coil is generated by magnetic field in the measuring transducer operation at least off and on flows through, this exciting current is particularly ambipolar and/or current strength is variable, drives by second effective voltage or by the secondary voltage that this voltage is derived.Should structure according to the present invention next is perfect, magnet exciting coil is by magnetic field and movable core interaction, and wherein field coil and movable core can move relative to each other.That should construct according to the present invention is another perfect, at least one measuring tube of measuring transducer is driven by the excitation system that forms by field coil and movable core, vibration at least off and in the measuring transducer operation, this excitation system is the particularly electronic excitation system of motor.

Field apparatus is perfect according to another of first scheme according to the present invention, and measuring transducer comprises two measuring tubes that are used for boot media, and they are fit into conduit and vibration at least off and in operation.

The 7th structure according to first scheme of field apparatus according to the present invention, measuring transducer is used to detect at least one parameter of the container that medium is housed, material level particularly, and this measuring transducer comprises that at least one stretches into measuring probe container intracavity or that communicate with inner chamber at least for this reason, microwave antenna particularly, the Gouboun-lead, vibration slip into body etc.

The 8th structure according to first scheme of field apparatus according to the present invention, field apparatus electronic system and external power source only is electrically connected by unique couple of conductor and this field apparatus electronic system particularly digital transient measurement value at least intermittently generation, that represent at least one measurement and/or monitoring parameter by this unique couple of conductor be transferred in the power supply externally and/or with analysis circuit that this power supply is electrically connected in.Improving that the present invention should construct, the supply current transient current intensity of particularly adjusting to the value between 4mA and the 20mA has been represented the measured value of instantaneous generation.

Basic design of the present invention is, customer in the field apparatus electronic system (except power supply circuits self) is divided into first circuit bank or the electric consumption device group with high priority on the one hand at least and has the second circuit group or the electric consumption device group of low priority, and on the other hand power supply is designed to, in the equipment normal running, to satisfy the power or the energy requirement of first circuit bank at least all the time at the scene.Thus, particularly act as power storage device interior and/or electric energy is assigned to the 3rd electric consumption device group by the circuit or the member of field apparatus dissipation at the scene, only when the first and second electric consumption device groups have enough power supply, this electric consumption device group is just flow through by electric current and electric energy is provided with this.

First circuit bank that will have a high priority is allocated at least one microprocessor and the telecommunication circuit that is used for communicating by letter with possible upper control unit in the field apparatus electronic system in the mode with advantage.Such advantage is, can keep on the one hand field apparatus all the time operation and on the other hand at least also can be online all the time.In addition, for field apparatus is the situation of measuring instrument, the measurement passage that is used to detect and prepares at least one measuring-signal mainly is allocated in first circuit bank, and what may exist mainly is that the excitation passage that is used to drive the electronic-physical measuring transducer can be used as the circuit with low priority and realizes.In measuring instrument, use in the situation of field apparatus electronic system of the present invention like this with vibration-type measuring transducer, particularly have advantage, promptly in fact whole, drive and in normal running, be provided all the time thus required electrical power to the measurement passage of microprocessor by first effective voltage of substantial constant adjustment by osciducer.Advantage is, all the time can the high-frequency scanning of same degree ground and the measuring tube vibration that generates according to operation with High-resolution Processing.In addition, even excitation channel part ground or fully driven by second effective voltage that changes in fact also can seamlessly encourage the measuring tube in the normal running all the time, if also amplitude to fluctuate in case of necessity.The present invention is based in addition and recognize, the not only temporary close of microprocessor, and for example encourage the driving in the gap of passage all can not cause the remarkable improvement of the energy balance of field apparatus.More will be according to circumstances, on the one hand for the operation of field apparatus and communicating by letter in case of necessity, for active member provide as far as possible all the time with enough energy and on the other hand, if necessary, few necessary member of trying one's best is depressurized power supply as required or closes.Demonstrate in addition, particularly continuous measurement or the field apparatus of approximate continuous measurement at least, Coriolis mass flowmeter for example, be to be worth very much like this, that is, can arrange electric energy and at first drop at least one microprocessor, particularly put into the processing and the analysis of measured value, for example put in the excitation system of sensing system, correspondingly only go to drive with the remaining energy of arranging.In this manner, though can not reach the signal to noise ratio of optimization for the measuring-signal that measuring transducer provides, but the mass defect that measuring-signal exists in case of necessity can without other and handle and analyze by measured value and compensate, the processing of measured value and analyze of the microprocessor realization of self-consistentency ground by efficient operation.

Other advantage of the present invention is, because the necessary small-power of operation makes field apparatus self observe the regulation of various explosion protection grades.Make thus field apparatus under ad hoc fashion, also be applicable to explosion hazard, only allow in the environment of inherently safe instrument.This field apparatus can be configured in addition, can with a kind of co-operate of common fieldbus.Can be on the one hand by with realize direct connection of fieldbus, for example, corresponding to the FELDBUS-agreement, (FELDBUS is the registered trade mark of FELDBUS FOUNDATION).Can realize co-operate indirectly by bus coupler on the other hand, for example corresponding to so-called HART-agreement (HART is the registered trade mark of HART User Group).

Description of drawings

Now the present invention is further explained according to embodiment and accompanying drawing.The part that function is identical is represented with like-identified in independent accompanying drawing, just repeats for significant demonstration in the accompanying drawing of back.

Fig. 1 is the side view of field apparatus and the external power source that is electrically connected by couple of conductor with this instrument,

Fig. 2 is suitable for first side view cutaway drawing that the part of the vibration-type measuring transducer of field apparatus embodiment among Fig. 1 is cut open,

Fig. 3 is the cutaway view of second side-looking of the measuring transducer of Fig. 2,

Fig. 4 is the embodiment of motor excitation system of the measuring transducer of Fig. 2,

Fig. 5 is the square circuit diagram, particularly two-wire field device that is fit to be applied to the field apparatus electronic system in the field apparatus,

Fig. 6 to Fig. 8 has shown that partly the application of the field apparatus of suitable Fig. 1 has the circuit diagram of block diagram form of embodiment of the vibration-type measuring transducer of Fig. 2 to Fig. 4,

Fig. 9 to Figure 12 is the embodiment circuit diagram that is fit to the end level of exciting circuit among Fig. 6 to Fig. 8.

Embodiment

Fig. 1 has shown an embodiment of the field apparatus with field apparatus electronic system 20 that is suitable for commercial measurement and automatic technology application, and this field apparatus electronic system is by external power source 70 power supplies.In the operation, external power source 70 provides a particularly unipolar supply power voltage U _vAnd external power source 70 is in company with exporting by supply power voltage U _vThe variable particularly ambipolar supply current I of respective drive.For this reason, the field apparatus electronic system is electrically connected by at least one pair of lead 2L with external power source 70 in operation.Since the voltage drop of Lock-in between the input of external power source 70 and field apparatus electronic system 20, supply power voltage U _vNaturally the terminal voltage U of reality in the time of also will being reduced to the field apparatus electronic system by this way and beginning _k

According to a structure of the present invention, the design of field apparatus electronic system and being arranged to, the electrical power of maximum conversion less than or maximum equal 1W.Another structure according to the present invention is designed to; the design of this field apparatus and being arranged to, it reached in the requirement of enough satisfying internal security blast (Ex-i) protection that for example European standard EN50 014 and EN50 020 propose aspect the explosive risk from safe coefficient.

According to another structure of the present invention, the measured value that this field apparatus is used for measuring and/or monitor at least one given physics of the medium that guides at pipeline and/or container and/or chemical parameters and repeats to provide corresponding this parameter of representative, this medium is gas and/or liquid particularly, parameter for example is a flow, density, viscosity, material level, pressure, temperature, pH value etc.This measuring instrument also comprises the measuring transducer of the physics-electronics that is electrically connected with the field apparatus electronic system for this reason, this measuring transducer is reacted to the variation of at least one parameter and is sent at least one measuring-signal corresponding with this parameter, particularly variable signal voltage and/or variable signal code at least off and on.Alternatively or replenish ground, electronic-physical regulating and controlling element with the electric coupling of field apparatus electronic system can be provided in the equipment at the scene, this regulating and controlling element is to react to the variation of the control signal of at least one setting to adjusting the influential adjustment action of parameter, signal voltage that described control signal is particularly variable and/or variable signal code, perhaps another kind of saying, field apparatus for example can be designed as at least one this physics and/or the chemical parameters that is used to adjust medium.In order to control field apparatus, particularly in order to trigger above-mentioned measuring transducer or, to provide built-in function and analysis circuit 50 at the scene in the equipment electronic system in addition in order to trigger above-mentioned regulating and controlling element.For field apparatus is the situation that is used to measure the measuring instrument of at least one given physics and/or chemical parameters, and operation and analysis circuit 50 are determined at least one measured value or a plurality of respective measurement values of parameter in addition.

The field apparatus that Fig. 1 shows is the on-line measurement instrument, especially for detecting medium, particularly gas and/or the parameter of liquid, for example quality that in (not showing) conduit, flows here, density and/or viscosity, and form the measured value X of instantaneous this parameter of representative _MThis field apparatus for example can be Coriolis mass flowmeter, density measure instrument, perhaps viscosity measurement instrument in view of the above.In order to generate at least one measuring-signal, the field apparatus of Xian Shiing comprises the field apparatus electronic system 20 that is positioned over the vibration-type measuring transducer 10 in the corresponding measuring transducer shell 100 and is positioned at electronic system shell 200 and is electrically connected in a suitable manner with measuring transducer 10 here.

The embodiment that has shown this measuring transducer in Fig. 2 to Fig. 4, its structure and mode of operation additionally also are described in detail in the US-A6006609.Point out at this, although the field apparatus that shows among the embodiment is the on-line measurement instrument with vibration-type measuring transducer, the present invention also can be converted to other field apparatuss, for example has the on-line sensor of magnetic induction measurement sensor or acoustic measurement transducer.Similarly, the present invention also can be used in the field apparatus of measurement parameter, and this parameter is determined for example material level and/or limiting condition jointly with the container that medium is housed.Such field apparatus usually realizes that by following measuring transducer this measuring transducer comprises that at least one stretches into measuring probe container intracavity or that communicate with inner chamber at least, microwave antenna for example, the Gouboun-lead, vibration slip into body etc.

For the guiding measuring medium, measuring transducer 10 according to the embodiment of Fig. 2 to Fig. 4 comprises that at least one has the measuring tube 13 of the entrance point 11 and the port of export 12, and this measuring tube has the measuring tube inner chamber 13A of elastically deformable in operation that can be given and internal diameter that can be given.The strain of measuring tube inner chamber 13A means, in order to generate reaction force aforementioned medium inside and that describe medium, with the spatial form of measuring tube inner chamber 13A and/or locus in the elastic range of measuring tube 13 with mode that can be given circularly, periodic variation particularly, for example referring to US-A4801897, US-A5648616, US-A5796011 or US-A6006609.If desired, for example can be with the measuring tube bending, as shown in EP-A1260798.Thus, for example replace unique measuring tube, also may adopt two bendings or straight measuring tube.Other suitable embodiment of this vibration-type measuring transducer for example are described in detail in US-B6711958, US-B6691583, US-B6666098, US-A5301557, US-A5357811, US-A5557973, US-A5602345 is among US-A5648616 or the US-A5796011.For the material of the straight type measuring tube 13 of Fig. 3 and Fig. 4, titanium alloy is particularly suitable.Also can replace titanium alloy and use other types, the normally used material of Wan Qu measuring tube particularly, stainless steel for example, tantalum or zircaloy etc.

Can be clamped in quiveringly in the bracing frame 14 with the measuring tube 13 that the conduit that medium is imported and derives communicates at import and outlet side in common mode, this bracing frame is hard, particularly bending and torsion rigidity and seal by measuring transducer shell 100.Bracing frame 14 is fixed in measuring tube 13 by import plate 213 and at outlet side by exit plate 223 at inlet side, and wherein these two plates are run through respectively by the corresponding extension device 131,132 of measuring tube 13.This outer support frame 14 comprises first side plate 24 and second side plate 34, these two side plates 24,34 are fixed in import plate 213 and exit plate 223 respectively as follows, promptly they in fact be parallel to measuring tube 13 and with measuring tube and to each other at a certain distance the configuration, referring to Fig. 3.The side that faces with each other of two side plates 24,34 is parallel to each other equally thus.Vertically rod 25 is to be fixed in side plate 24,34 with measuring tube 13 mode apart, as the counterweight of the vibration of eliminating measuring tube 13.Show that as Fig. 4 vertically the excellent 25 whole length of vibrating that in fact are parallel to measuring tube 13 are extended; But this is not necessary, and vertically rod 25 natures can require and implement shortly.Bracing frame 14 with two side plates 24,34, import plate 213, exit plate 223 and vertical rod 25 has the longitudinal center of gravity line, and this center of gravity line is parallel to the measuring tube axis 13B of the virtual connection entrance point 11 and the port of export 12.Among Fig. 3 and Fig. 4 by head of screw shown side plate 24,34 import plate 213, exit plate 223 and vertically the said fixing of rod 25 can realize by spinning; Also can adopt other other fixed forms well known to those skilled in the art.Be removably installed in the situation of conduit for measuring transducer 10, measuring tube 13 entrance points molded first flange 119 and the port of export molded second flange 120, referring to Fig. 1; Also can replace flange 19,20 by other pipe joint elements that is used for removably connecting with conduit, for example the so-called three-dimensional clip that shows as Fig. 3 connects.If desired, measuring tube 13 also can for example be directly connected in conduit by welding or hard solder etc.

In order to generate the reaction force in the aforesaid medium, measuring tube 13 is in the operating process of measuring transducer 10, drive by electricity-machine excitation system 16 with the measuring tube coupling, with frequency of oscillation that can be given, particularly natural resonance frequency vibrates and the elastic deformation in given mode thus under so-called effective model.As previously mentioned, this resonance frequency also depends on the instantaneous density of liquid.In the embodiment that shows, the measuring tube 13 of vibration is by the resting position particularly lateral deflection spatially of static state, as the normal conditions in this vibration-type measuring transducer; Same also is effective to such measuring transducer, be that one or more crooked measuring tube is implemented cantilever vibration around the longitudinal axis of the imagination of the corresponding virtual connection entrance point respectively and the port of export, perhaps for these measuring transducers, one or more straight measuring tube also can only be carried out smooth flexural vibrations around the measuring tube longitudinal axis.In another situation, for example described in the WO-A95/16897, measuring transducer 10 is carried out the radiation vibration of wriggling, so the cross section of vibration measurement pipe symmetric deformation in due form, the measuring tube longitudinal axis is retained in its static resting position.

Excitation system 16 is used for, by conversion by operation and analysis circuit 50 with the Electron Excitation power P of electrical drive signal form feed-in _Exe, nucleus formation is in the exciting force F of measuring tube 13 _ExeIn the excitation on natural resonance frequency, exciting power P _ExeIn fact only as compensation through the power component of depriving with friction liquid internal and by vibrational system machinery.In order to reach high as far as possible efficient, thus with exciting power P _ExeBe adjusted into the vibration that in the effective model of expectation, keeps measuring tube basically, for example vibration of fundamental resonance frequency as much as possible exactly.For with exciting force F _ExeBe delivered to measuring tube 13, as shown in Figure 5, excitation system 16 comprises leverage 15 rigidity, electromagnetism and/or motorized motions, and this leverage has cantilever 154 and the yoke 163 that measuring tube 13 is fixed in bending resistance.This yoke 163 too bending resistance be fixed in cantilever 154 have the end of certain distance with measuring tube 13, and be disposed at measuring tube 13 upsides and be transverse to measuring tube.For example cantilever 154 can be for being contained in measuring tube a sheet metal in the boring.For other suitable embodiment of leverage 15, can consult the US-A6006609 that has mentioned.In contrast to Fig. 5, leverage 15 is the T-type and is configured to, and acts on the measuring tube 13 about the middle of the import and the port of export 11,12 greatly, and measuring tube can be known the lateral deflection that it is maximum in operation whereby.According to Fig. 5, in order to reach the purpose of activation lever mechanism 15, excitation system 16 comprises first magnet exciting coil 26 and the affiliated first permanent magnetism iron core 27 and second magnet exciting coil 36 and the second affiliated permanent magnetism iron core 37.These two magnet exciting coils 26,36 are preferably series connection, particularly removably are fixed in bracing frame 14 measuring tube 13 both sides, below the yoke 163, and 37 interact in operation in other words with iron core 27 respectively.These two magnet exciting coils 26,36 should require also can and to connect certainly.As Fig. 3 and shown in Figure 5, two iron cores 27,37 are fixed in yoke 163 as follows at a certain distance, promptly in the operating process of measuring transducer 10, in fact iron core 27 is run through by the magnetic field of magnet exciting coil 26 and in fact iron core 37 is run through by the magnetic field of magnet exciting coil 36 and owing to corresponding electronic and/or electromagnetic force effect is moved, particularly stretch into affiliated magnet exciting coil respectively.By the motion of the iron core that magnetic field generated 27,37 of magnet exciting coil 26,36,, be transferred on the measuring tube 13 by yoke 163 and cantilever 154, wherein iron core 27,37 particularly also act as movable core.Iron core 27,37 is to form like this with respect to the motion of magnetic coil under respectively, promptly yoke 163 by its resting position alternately to side plate 24 directions and side plate 34 direction deflections.Article one, corresponding, the pivot center that is parallel to the leverage 15 of described measuring tube-axis 13B for example can pass cantilever 154 and distribute.Bracing frame 14 as excitation system 16 support components comprises the strutting piece 29 that particularly removably connects with side plate 24,34 in addition, is used for magnet exciting coil 26,36 and the support of the single member in case of necessity of the electormagnetic braking sytem 217 of explanation soon.

In the embodiment of measuring transducer 10, fixed clamp causes the strain of its measuring tube inner chamber 13A simultaneously in the lateral deflection of the measuring tube 13 of the vibration of the entrance point 11 and the port of export 12, and in fact this strain constitutes on the whole length of measuring tube 13.In this external measuring tube 13, because the moment of torsion that leverage 15 acts on measuring tube causes the reversing of discontinuous at least around measuring tube-axis 13B to the lateral deflection meeting simultaneously, so measuring tube 13 is in fact to vibrate as the crooked vibration-torsional mode of the mixing of effective model.Wherein can form reversing of measuring tube 13 like this, promptly with the lateral deflection of measuring tube 13 cantilever 154 ends apart or in the same way in or be in reverse to the lateral deflection of measuring tube 13.Measuring tube 13 can be to be equivalent to the first crooked vibration-torsional mode under the situation in the same way or to implement torsional oscillation to be equivalent to the bending vibration-torsional mode of second under the inversion condition.According to the measuring transducer 10 of this embodiment, for example natural basis-the resonance frequency of second of the 900Hz crooked vibration-torsional mode is approximate double in the first crooked vibration-torsional mode then.Only carry out the situations of vibrating with the second crooked vibration-torsional mode in operation for measuring tube 13, integrated electormagnetic braking sytem 217 based on vortex principle in excitation system 16 is used for the position of firm such rotation axis.Can guarantee by electormagnetic braking sytem 217, measuring tube 13 is all the time with the second crooked vibration-torsional mode vibration, and the possible interference effect that acts on measuring tube 13 can not cause automatic conversion, particularly can not cause the conversion that changes the first crooked vibration-torsional mode over to.The details of electormagnetic braking sytem has a detailed description in US-A6006609.

In order to make measuring tube 13 vibration, excitation system 16 particularly has adjustable amplitude and an adjustable driving frequency f by same vibration in operation _ExeExciting current i _ExeAnd power the required magnetic field of motion that this exciting current flows through the magnet

exciting coil

26,36 in the operation and produces

iron core

27,37 with corresponding manner.Show as the signal of Fig. 2, comprise that the driver element 50B in the equipment electronic system 20 at the scene provides exciting current i outward thus _ExeAnd this electric current for example can be harmonic alternating current.According to the embodiment of Fig. 2 to Fig. 4, in the application of measuring transducer, exciting current i _ExeDriving frequency f _ExePreferably select or be adjusted into, the measuring tube 13 of swaying is as far as possible only with the second crooked vibration-torsional mode vibration.

Also to mention, even in the embodiment of this demonstration, field apparatus electronic system 20 includes only a variable induction impedance (being the magnet exciting coil of variable inductance here) by driver element 50B power supply, also this driver element 50B can be designed to encourage other electrical impedance, for example measurement electric capacity of variable capacitance etc.For capacitive pressure transducer is the situation of measuring transducer, this electrical impedance depends at least one measurement and/or monitoring parameter and changes in operating process, as everyone knows, by this signal voltage that reduces from the power transformation impedance and/or flow through this from signal code of power transformation impedance as measuring-signal.

In order to detect the distortion of measuring tube 13, as Fig. 2, shown in 3, measuring transducer 10 comprises sensing system in addition, this system by at least one first sensing element 17 that vibration is made a response to measuring tube 13 generate one represent this vibration as measuring-signal S ₁The first oscillation measurement signal.Sensing element 17 for example can be made of the permanent magnetism iron core, and for example sensing element 17 can be made of the permanent magnetism iron core, and this iron core is fixed in measuring tube 13 and interacts with magnet exciting coil, and this magnet exciting coil is supported by bracing frame 14.What be particularly suitable as sensing element 17 is those elements of gathering the deflection speed of measuring tube 13 based on electric principle.Also can adopt electric resistance sensor electrokinetic transducer or measuring distance or the optical pickocff of measuring acceleration.The transducer that the suitable detection that can certainly adopt other those skilled in the art to be familiar with is vibrated.Sensing system also comprises special second sensing element 18 identical with first sensing element 17 in addition, and this sensing element is same to be generated one and represent the second oscillation measurement signal that measuring tube vibrates as the second measuring-signal S ₂In an embodiment in the measuring transducer of Xian Shiing, these two sensor elements 17,18 particularly with the centre distance of measuring tube 13 equally each other apart along measuring tube 13, and following configuration, promptly by this transducer 17,18 not only at inlet side also in the vibration of outlet side collection in worksite measuring tube 13 and form corresponding oscillation measurement signal.

Illustrated the structure of the field apparatus electronic system of field apparatus among a kind of suitable Fig. 1 to Fig. 4 in the mode of square circuit diagram among Fig. 5 in addition.Fig. 5 has illustrated on the right side to have the above-mentioned vibration-type measuring transducer of excitation system 16 and sensor-based

system

17,18, has wherein only symbolically shown the required magnet exciting coil of measuring principle of measuring transducer.

As shown in Figure 2, with the first measuring-signal S ₁The second measuring-signal S of Cun Zaiing in case of necessity ₂Preferred operation and the analysis circuit analytic unit 50A for numeral that provide in the equipment electronic system 20 at the scene are provided, and wherein first measuring-signal and second measuring-signal comprise all that usually each is equivalent to the signal frequency of measuring tube 13 ringing frequencies.Analytic unit 50A is used for the measured value X that the procedure parameter that instantaneous representative will be gathered is determined on numerical value ground particularly _M, and this measured value is converted into accordingly at operation and the detectable measured value signal X of analysis circuit output _M, procedure parameter for example is a mass flow here, density, viscosity etc.Here the measuring transducer of Xian Shiing is according to the measuring-signal S that exists ₁, S ₂In unique one can determine density or viscosity fully, and for the measurement of mass flow, the technical staff uses two measuring-signal S with knowing ₁And S ₂So, determine to differ, for example in signal-time range or signal-frequency range with mass flow is corresponding.

According to a kind of structure of the present invention, realize analytic unit 50A by using the microcomputer μ C in the equipment electronic system at the scene 20, this microcomputer is programmed for corresponding manner, the measuring-signal that transmits according to sensor-based

system

17,18 and digitally determine measured value X _MCan adopt for example suitable microprocessor and/or advanced signal processor for the realization of microcomputer.As shown in Figure 5, analytic unit 50A comprises at least one A/D converter in addition, by this transducer with measuring-signal S ₁, S ₂One of digitlization guide to this microprocessor, perhaps particularly usually will be by two measuring-signal S before as coriolis mass flow sensor ₁, S ₂Guide to the signal difference digitlization of deriving this microprocessor.Can be further analytic unit 50A adnation be become and/or the measurement that receives-or operating data volatibility ground or permanently store the corresponding digital memory RAM into, in the EEPROM.

As previously mentioned, operation and analysis circuit 50 comprise driver element 50B in addition, and this driver element is used for described exciting current i _ExeBe excitation system 16 power supplies, and in fact constituted regulating loop with measuring tube 13.This regulating loop is designed to, be modulated to by electronics measuring tube 13 excited vibration mechanical resonant frequency and by the given vibration amplitude of reference signal Sr.Driver element 50B can form by so-called PLL phase-locked loop in due form, is used for the electricity adjustment that resonance frequency also has the drive signal phase place; And, be used for the electricity adjustment of drive signal amplitude and vibration amplitude by the formation of corresponding amplitude adjustment level.

As shown in Figure 5, driver element 50B also is connected in the analytic unit of particularly aforementioned microprocessor μ C, for example driver element 50B receives the action required data from analytic unit, as the instantaneous driving frequency that will adjust and/or be used for the instantaneous amplitude that will adjust of exciting current and the phase place that will adjust in case of necessity, perhaps send the inner adjustment signal that generates of driver element 50B and/or adjust parameter to this analytic unit, this is adjusted signal and/or adjusts parameter particularly about adjusted exciting current i _ExeAnd/or the exciting power P in the feed-in measuring transducer _ExeInformation.The operating data of driver element 50B, driving frequency, amplitude and/or phase place can also can be relative set-point for absolute set-point.Alternatively or replenish ground, the operating data that is transferred to driver element 50B can be represented driving frequency, the variation that the variation that increases progressively of amplitude and/or phase place is successively decreased in other words.Extraly for microprocessor μ C, for example operation and analysis circuit 50 also can comprise and be used for the signal generator that drive signal generates, for example digital signal processor or accordingly as the signal generator structure, particularly the FPGA (Field Programmable Gate Array) member of FPGA.

Fig. 6 to 12 has shown the embodiment of driver element 50B in the mode of square circuit diagram, also is suitable for the application of self-shield measuring instrument especially and/or as the field apparatus of 2L measuring instrument configuration.

In first scheme, one of transducing signal that transducer 17,18 is carried or also their summation can be guided to amplitude demodulation level pd as input signal, one of amplitude demodulation level pd input side and transducer 17,18 connection thus is transducer 17 among Fig. 6.Amplitude demodulation level pd is used for determining continuously the amplitude of oscillation of measuring tube vibration.Amplitude demodulation level pd also is used to carry for example output signal of simple straight signal in addition, the amplitude of oscillation that this output signal representative is gathered.The peak detector of input signal is provided in the preferable configuration of amplitude demodulation level pd of the present invention for this reason.For example also can adopt the synchronous rectifier that is used for the amplitude of oscillation collection and replace peak detector, this synchronous rectifier is by sending clock with the reference signal of input signal same phase.The first input end of contrast level sa is connected in the output of amplitude demodulation level pd; Adjustable reference signal Sr is directed to second input of contrast level Sa, the vibration amplitude of this signal feeding measuring tube 13.The output signal of contrast level sa decision amplitude demodulation level pd and the deviation of reference signal Sr are also exported this deviation with corresponding output signal.For example this deviation can be under the use of simple difference and determine or continue to transmit with the absolute amplitude errors of form, this simple difference for gather and by the given amplitude of oscillation difference of reference signal Sr; Perhaps for example under the use of ratio and determine or continue to transmit with the relative amplitude error, this ratio is that gather and given amplitude of oscillation ratio.The input signal of amplitude demodulation level pd is directed to the first input end of Modulation and Amplitude Modulation level am1 and the output signal of contrast level sa is directed to second input.Modulation and Amplitude Modulation level am1 is used for the input signal with the output amplitude modulated amplitude demodulation stae pd of contrast level sa.For example wherein, transducing signal S ₁One of, two transducing signal S ₁, S ₂Sum or one pro rata for example by accordingly, the artificial signal that generates of the signal generator of numeral particularly, can be used as input signal and thus as complete variable carrier signal on its frequency, on this signal, modulated by contrast level sa and generated the error signal of variable amplitude.This error signal has shown the deviation between measuring tube 13 transient vibration amplitudes and its specified amplitude of oscillation, and this specified amplitude of oscillation is represented by reference signal Sr.Modulation and Amplitude Modulation level am1 also is used to excitation system 16 to provide and is loaded with the drive signal that drives energy in addition.The Modulation and Amplitude Modulation level comprises corresponding end level ps for this reason, is used for amplifying with the modulation signal modulated carrier signal.In contrast to Fig. 6,, in Modulation and Amplitude Modulation level am1, also provide multiplier m1 for modulation signal modulated carrier signal amplitude.

Mode with square circuit diagram in Fig. 7 has partly shown according to the present invention the alternative plan circuit diagram of the driver element 50B of alternative plan.The embodiment of Fig. 7 promptly replaces Modulation and Amplitude Modulation level am by pulse-width modulation level pwm basically by the following embodiment that is different from Fig. 6, and this pulse-width modulation level pwm has the pulse width modulator pm that clock is provided with outside alternating signal.As shown in Figure 7, pulse width modulator pm is with the operation of the constant first positive direct voltage+U1 and be in circuit SN at zero point.The input signal of amplitude demodulation level pd is guided to the first input end (input of carrier signal) of pulse width modulator pm.This first input end is connected in a transducer (being transducer 17 among Fig. 7 again) thus.Error signal is guided to second input (modulation signal input) of pulse width modulator pm, and this error signal is proportional with the amplitude error of determining.The output of pulse width modulator pm is connected in an input that finishes level ps ' again, and this end level provides the corresponding driving signal at outlet side to excitation system 16.The drive signal that is provided by end level ps ' is square-wave signal here, and its signal frequency with the input signal of amplitude demodulation level pd is clock and comprises a pulsewidth of modulating with contrast level sa output signal.

The third party's case circuit diagram that has partly shown driver element 50B in Fig. 8 in the mode of square circuit diagram.The embodiment of Fig. 8 is basically by the following embodiment that is different from Fig. 6, promptly replaces multiplier m1 by comparator kk and dc voltage changer dc, and this transducer provides at least one to drive exciting current i _ExeDriving voltage.The amplitude of this driving voltage depends on the output signal of contrast level sa again and therefore is thought of as non-constant.According to the design of driving voltage, exciting current i _ExeAs previously mentioned, can be bipolar or one pole.Therefore according to a preferred embodiment of the invention, DC voltage converter dc provides the driving voltage of the second current potential-u that has the first positive current potential+u and bear, the wherein operation of DC voltage converter dc-input receives the output signal of contrast level sa, and this operation-input is used for the current potential adjustment.The driving voltage that the amplitude that is provided by DC voltage converter dc is suitably adjusted is applied in the end level ps of the pulse-width modulation level pwm that is used for excitation system 16 power supplies as operating voltage "." input side is connected in the output of comparator kk to finish level ps in addition.Comparator kk is with constant, positive first direct voltage+U1 operation and be in circuit SN at zero point.The input signal of peak detector pd guides to the input of comparator kk.Thus, comparator kk input side is connected in a transducer (being transducer 17 among Fig. 8 again).

Dotted line among Fig. 6 to 7 means respectively, can replace single transducing signal by the transducing signal sum of transducer 17,18 and guides to peak detector pd and multiplier m1 pulse width modulator pm comparator kk in other words in other words; Then these transducing signals are guided by adder.Alternatively, as previously mentioned, the manual signal that also can adopt the frequency that generates by digital signal processor and the D/A converter that is connected with its output and phase place to adjust accordingly by transducing signal.In Fig. 6 to 7, can also see the partial circuit figure that other dotted line is represented, shown the better perfect of preferred exciting circuit.In the example of driver element 50B is improved, amplifier vv is provided, this amplifier is connected in series with peak detector pd or is connected in series with synchronous rectifier in case of necessity.In another of driver element 50B improves, amplifier v is provided, the output signal that this amplifier will contrast level sa is before as error signal arrival Modulation and Amplitude Modulation level am and amplify.Such amplifier can be operational amplifier op, and its positive input is in circuit SN at zero point, and its reverse input end is connected in the output of contrast level sa and is connected in amplifier out by parallel resistance ws by series resistance wv.The operational amplifier op of this cloth diagram form lays respectively at the upper right side of Fig. 6 to 7.In another the improving of driver element 50B, integral amplifier vi is provided, this amplifier will contrast the output signal of level sa and amplify and integration before arriving multiplier m as error signal.Such amplifier can be operational amplifier op ', its positive input is in circuit SN at zero point, and its reverse input end is connected in the output of contrast level sa and is connected in amplifier out by the series circuit of being made up of parallel resistance ws ' and capacitor k by series resistance wv '.The operational amplifier op ' of this cloth diagram form lays respectively in the middle of the right side of Fig. 6 to 7.

Another of driver element 50B improves and is that difference integral amplifier vd, this amplifier will contrast output signal amplification before arriving multiplier m1 as error signal, difference and the integration of level sa.Such amplifier can be operational amplifier op "; its positive input is in circuit SN at zero point, and its reverse input end is connected in amplifier out by the series circuit that the series resistance wv " with the parallel circuits of the first electric capacity k1 be connected in the output of contrast level sa and by by parallel resistance ws " and the second capacitor k2 form.The operational amplifier op of this cloth diagram form " lays respectively at the lower right side of Fig. 6 to 7.Represented by arrow among Fig. 6 to 7, with each amplifier v, the square frame q place that vi, vd place dotted line to represent, this square frame or between contrast level sa output and Modulation and Amplitude Modulation level am second input or between contrast level sa output and pulse-width modulation level pwm modulation signal input.

In framework of the present invention, partial circuit function independent in Fig. 6 to 7 realizes by corresponding simulation or numerical portion circuit, in the latter's situation, for example realize that the signal that wherein will guide to this microprocessor will will be changed through digital-to-analog too through analog/digital conversion and its output signal before by the microprocessor of suitable programming.

Shown the circuit diagram that finishes level ps first embodiment among Fig. 9, for example can insert in the Modulation and Amplitude Modulation level am according to Fig. 6.Operational amplifier ov is with positive and negative, constant DC pressures+U respectively, and-U operates and following wiring, and its reverse input end is in circuit SN at zero point by the first resistance w1, and its positive input is in the output of multiplier m1 by the second resistance w2.The output of operational amplifier ov is connected in first utmost point pp1 of the elementary winding of transformer tf by the intermediate circuit of the 3rd resistance w3; Second utmost point pp2 of elementary winding is in circuit SN at zero point.Transformer tf also has a secondary winding, and it is by the two poles of the earth sp1, and sp2 is connected with excitation system 16.

Elementary winding has elementary number of windings N1 and secondary winding and has secondary winding and count N2.Transformer tf is electric current-rising transformer and has for example 20: 1 transformation ratio N1/N2.The reverse input end of operational amplifier ov is connected with first utmost point pp1 of elementary winding by the 4th resistance w4.Its positive input is connected in output by the 5th resistance w5.Five resistance w1, w2, w3, w4 and w5 have respective resistance values R1 respectively, R2, R3, R4, and R5.Resistance R1 is chosen to be and equals resistance R2 and resistance R4 and be chosen to be and equal resistance R5.If represent the output voltage of multiplier m with um, then the alternating current i that flow in the excitation system 16 can followingly draw: R5N1 1=um m R1 R3 N2.Shown the circuit diagram that finishes level ps ' second embodiment among Figure 10, for example can insert in the pulse-width modulation level pwm according to Fig. 7." core " that this additional push-pull type finishes the level structure is the series circuit of the Control current path of P raceway groove-reinforcement-insulating barrier-field-effect transistor P (hereinafter to be referred as transistor) and N raceway groove-reinforcement-insulating barrier-field-effect transistor N.Tie point at the Control current path has connected excitation system 16.For each bar Control current path parallel connection protection diode dn, dp, wherein the transistor that is connected to separately of negative electrode is separately gone up on schedule.The end that the end of series circuit P transistor side is applied in constant positive second direct voltage+U2 and its N transistor side is applied in corresponding constant negative dc voltage-U2.Transistor N, P controls the output that the utmost point is connected to each other and is connected in comparator kk '.The positive input of comparator kk ' is connected to the output of pulse width modulator pm, in contrast to Fig. 7.The reverse input end of comparator kk ' is connected in the tapping point of voltage divider, and this voltage divider is made up of resistance r1 and resistance r2.Resistance r1, r2 have identical resistance and be in positive direct voltage+U1 and circuit SN at zero point between.Resistance r1, r2 and comparator kk ' are used for the symmetry of the output signal of pulse width modulator pm about direct voltage+U1 half value.When excitation system 16 is passed zero point at the each forward of output signal sum of the output signal of transducer 17 or transducer 17,18, receive positive current pulses; When the each negative sense of output signal sum of the output signal of transducer 17 or transducer 17,18 passes zero point, receive negative current pulse.For reaching the amplitude of oscillation by the given measuring tube 13 of reference signal Sr, pulse duration is separately adjusted automatically.

Shown among Figure 11 that " circuit diagram of another embodiment for example can insert in the Modulation and Amplitude Modulation level am1 according to Fig. 8 an end level ps.This also is as shown in figure 10 for replenishing " core " that push-pull type finishes the level structure again, the series circuit of P raceway groove-reinforcement-insulating barrier-field-effect transistor P ' and the Control current path of N raceway groove-reinforcement-insulating barrier-field-effect transistor N '.Tie point at the Control current path has connected excitation system 16.For each bar Control current path parallel connection protection diode dn ', dp ', wherein the transistor that is connected to separately of negative electrode is separately gone up on schedule.The end of series circuit P transistor side is applied in positive direct-current voltages+U2, and this positive direct-current voltages depends on the output signal of contrast level sa and the end of its N transistor side is applied in negative dc voltage-U2, and this negative dc voltage depends on the output signal of contrast level sa.Transistor N ', the P ' control utmost point is connected to each other and is connected in comparator kk " output.Comparator kk " positive input be connected to the output of comparator kk, in contrast to Fig. 8.Comparator kk " reverse input end be connected in the tapping point of voltage divider, this voltage divider is made up of resistance r3 and resistance r4.Resistance r3, r4 have identical resistance and be in positive direct-current voltages+U1 and circuit SN at zero point between.Resistance r3, r4 and comparator kk " are used for the symmetry of the output signal of comparator kk about direct voltage+U1 half value.Excitation system 16 receives positive current pulses during each positive half wave of the output signal sum of the output signal of transducer 17 or transducer 17,18; During each negative half-wave of the output signal sum of the output signal of transducer 17 or transducer 17,18, receive negative current pulse.Current impulse amplitude dependence separately is in the direct voltage+U of self side, and-U, this direct voltage depend on the output signal of contrast level sa again, so can be adjusted automatically by the amplitude of oscillation of the given measuring tube 13 of reference signal Sr.

The last embodiment that in Figure 12, has schematically shown hybrid drive unit 50B in the mode of square circuit diagram, its part operation be numeral with part operation for simulating.Driver element 50B comprises digital signal generator, is used for the set-point of the particularly numerical value that will be generated by microcomputer 50A, is converted to the corresponding digital oscillator signal, and this set-point for example is exciting current i _ExeAmplitude, the set-point of the phase place of pumping signal and/or its frequency of oscillation equal excitation signal individual parameter.Independent parameter as previously mentioned, can be used as absolute value and/or the value that reduces in other words as the value that increases sends driver element 50B to.

As previously mentioned, field apparatus electronic system and field apparatus are by external power source 70 power supplies, measurement translator-the charger of Remote configuration etc. for example, this charger is connected with field apparatus electronic system 20 with field apparatus or more definite theory by at least one two-conductor line 2L.For example this measurement translator-charger can be connected by the field bus system upper level Process Control System indoor with being in process control again.Here among the embodiment of Xian Shiing, as common in the extensive application of commercial measurement and automatic technology, the field apparatus electronic system only effectively is electrically connected by a unique two-conductor line 2L at least off and on external power source in addition.Correspondingly, the field apparatus electronic system is on the one hand by this two-conductor line power supply, and on the other hand, the field apparatus electronic system is the measured value signal X of generation at least intermittently _MAlso identical by this two-conductor line 2L be sent to be disposed in the external power source 70 and/or with the external analysis circuit 80 of power supply electric coupling.For example connect measurement translator-charger and field apparatus unique here two-conductor line 2L can with power supply 71 and the measuring resistance R of feed-in supply current I _MBe connected in series, for example this power supply can be battery, perhaps the DC source of being powered by the in-line power net.Power supply 70 provides supply current I and is field apparatus electronic system 20 power supply to operate required electric energy.Measuring resistance R _MHave two measurement terminal 72,73 in addition, can on this terminal, detect and represent transient measurement value X _MSupply current and with the proportional measuring voltage U of electric current _MMeasuring voltage U for example _MCan the on-the-spot measured value processing unit that shows or guide to upper level.Here unique two-conductor line 2L for example can be used as so-called two-wire system current circuit, particularly 4mA-20mA current circuit, perhaps as the bonding conductor to the external digital fieldbus, for example PROFIBUS-PA or FOUNDATION FIELDBUS.

In addition according to another structure of the present invention, with transient measurement value X _MBe modulated on the supply current I.For example can be by instantaneous, the particularly current strength representative between 4mA and 20mA of supply current I by the transient measurement value of field apparatus decision, this supply current I flows in the two-conductor line 2L that constitutes the two-wire system current circuit.

Another structure according to the present invention in addition provides field apparatus to communicate by letter by data transmission system with peripheral operation and control unit at least off and on, for example this peripheral operation and control unit can be manual operating instrument or Programmable Logic Controller (SPS), and communication can be exchange field apparatus particular data.Also provide telecommunication circuit COM in the equipment electronic system 20 at the scene, this telecommunication circuit control and operation communicating by letter by data transmission system for this reason.For example except measured value X _MTelecommunication circuit also is used in particular for other inside field apparatus-parameter is converted to the signal that can transmit by two-conductor line 2L and this signal is coupled into lead.Alternatively or replenish ground, also telecommunication circuit COM can be designed to the field device parameters that corresponding reception is sent through two-conductor line 2L by the outside.For example telecommunication circuit COM can be for according to HART CommunicationFoundation, the interface circuit of the HART@-on-scene communication agreement work of Austin TX, this interface circuit has adopted the high-frequency alternating current of FSK-coding as signal carrier, only is connected in the situation of external power source especially by the two-wire system loop for field apparatus in the aforementioned operation.

By the combination of Fig. 1 and 5 as can be seen, be voltage and/or the electric current of adjusting and regulate field apparatus inside, field apparatus electronic system 20 also comprises the current regulator IS that at least one is flow through by supply current I in addition ₁, be used for adjusting and/or the clock of modulation supply current I, particularly supply current.Also provide in-line power circuit 40 in the equipment electronic system 20 at the scene in addition, this in-line power circuit is applied in the inside input voltage U of field apparatus electronic system 20 _eAnd be used to built-in function and analysis circuit 50 power supplies, this inside input voltage U _eBy terminal voltage U _KDividing potential drop.

In order to gather and be adjusted at the voltage and/or the instantaneous mobile electric current of instantaneous decline in the field apparatus electronic system 20, power supply circuits 40 comprise in addition to be measured and regulon 60.And particularly for aforementioned with measured value X _MBe modulated to the situation of supply current I, measurement and regulon 60 also are used for what sent by Operations Analyst circuit 50, represent the measured value X of instantaneous generation _MMeasured value signal X _MBe converted into the first current regulating signal I _Stell, this first current regulating signal is corresponding to current regulator IS ₁Adjust with supply current.Measure and regulon 60 and current regulator IS ₁In fact jointly constitute the electric current flow straightener-vertical flow straightener of so-called linearity of supply current here.According to a structure of the present invention, with current regulating signal I _StellBe designed to, aforementioned flow straightener is according to the measured value X of instantaneous decision _MBe adjusted into this measured value supply current I proportional.Alternatively or replenish ground, current regulating signal I _StellConstitute, flow straightener sends clock to supply current I, for example in order to reach according to the communication objective of PROFIBUS-PA standard and binary coding.For generate the representative corresponding electric current particularly basically with the proportional detection voltage of electric current I _1-ist, I _2-ist, I _3-ist, also correspondingly provide in these external power supply circuits 40 at least off and on by supply current or by the shunting I of this electric current ₁, I ₂, I ₃The detection resistance R that flows through ₁, R ₂, R ₃

At least for aforementioned in order to show measured value X _MAnd the amplitude of modulation supply current I and because the limited electrical power of external power source and the supply power voltage U that provides by external power source _vThe terminal voltage U of Chu Xianing thereupon _kCorresponding reduction or the situation of corresponding rising along with the supply current I that reduces on the contrary with the supply current I that raises, supply power voltage U _vWith terminal voltage U _kMagnitude of voltage fluctuate in unpredictalbe mode and they be considered as in operation changing with significant degree.When field apparatus as described above, when operating with the permanent accepted standard of commercial measurement technology 4mA to 20mA, the electrical power that the current range below the 4mA only is provided and about 40 to 90mW (=milliwatts) only are provided all the time according to the supply power voltage value for the power supply of normal running.

As shown in Figure 5, power supply circuits 40 also comprise by measuring and the pressurizers 30 of regulon 60 excitations at first in addition, and it is the inside input voltage U of in-line power with the field apparatus electronic system as primary voltage or base voltage that this pressurizer is used for _eAdjust to as far as possible exactly can be given operation in case of necessity on the variable level and at least in the normal running of non-interference, should inside input voltage U _eConstant as far as possible remaining on the instantaneous selected level, wherein terminal voltage U _kAt least equal minimum voltage value U _{K_min}This external pelivimetry and regulon 60 and the inner input voltage U of pressurizer 30 common formations _eThe input voltage voltage regulator, be used in particular for as far as possible accurately adjusting inner input voltage and keeping continual and steady.Also show,, keep inner input voltage U like this according to a structure of the present invention as Figure 13 _eLevel, promptly inner input voltage U _eAll the time be lower than terminal voltage U _kWherein inner input voltage U _eThe level that keeps by aforesaid input voltage regulation device 30,60, for example depending on instantaneous mobile supply current I in operation can change this level basically continuously.Alternatively, also can be with level in certain current strength scope of supply current I and at terminal voltage U _kThe relevant voltage scope on keep changing (as representing by chain line among Figure 13) constant and interimly, for example when surpassing or not enough corresponding supply current I and/or terminal voltage U _kDuring given threshold value.According to another structure of the present invention, input voltage regulation device 30,60 is designed to, at the maximum voltage value U that reaches for example 15v order of magnitude given or can be given _{E_max}After, although terminal voltage U _kMay also can continue to raise for example surpasses 20v, also this level is kept constant.Therefore, the effect of input voltage regulation device 30,60 not only is inner input voltage U _eVoltage

Voltage regulator, and be voltage limiter.

For the continuation internal distribution of the electric energy of the independent member of field apparatus electronic system or assembly, this electronic system comprises in addition and transforms stable inside input voltage U _eThe first effective voltage adjuster UR ₁, this voltage regulator is shunted I by first of variable especially supply current I at least off and on ₁Flow through and be used to provide substantial constant to adjust to the first level U _{N1_soll}On the first inner effective voltage U of field apparatus electronic system 20 _N1, this first level U _{N1_soll}Can be given, parameterisable in case of necessity.Provide too in these external power supply circuits 40 and transformed stable inside input voltage U _eThe second effective voltage adjuster UR ₂, this voltage regulator is shunted I by first of particularly variable supply current I at least off and on ₂Flow through.This second effective voltage adjuster UR ₂Be used to provide the second inner effective voltage U in the field apparatus electronic system 20 again _N2, this second inner effective voltage U _N2Variable in voltage range that can be given.For in the field apparatus electronic system to the only effective voltage U of momentary load situation _N2Magnitude of voltage, for example can measure and regulon 60 sides have been considered the momentary load situation in the field apparatus electronic system and determined and with correspondent voltage operation signal U _{N2_soll}Form be sent to effective voltage adjuster UR ₂The linear rectifier that for example can adopt so-called switching and rectifying and/or non-clock oscillation is as effective voltage adjuster UR ₁, UR ₂, and pressurizer 30 and input voltage regulation device can be by shunt regulator IS ₂Constitute, for example this shunt regulator IS ₂Be applied in inner input voltage U by bypass _e, realize by transistor and/or adjustable Zener diode.

Thus as shown in Figure 5, the input voltage regulation device is designed to, and shunts I by variable especially supply current I the 3rd at least off and in normal running ₃Flow through, wherein measurement and regulon 60 provide the second current regulating signal I _{3_stell}, this second current regulating signal I _{3_stell}Corresponding control pressurizer 30 (is shunt regulator IS here ₂) and determine the 3rd shunting.When instantaneous governable electrical power surpassed the required electrical power of operation and the instantaneous reality of analysis circuit 50 sides in the equipment electronic system 20 at the scene, wherein governable electrical power was by keeping constant inside input voltage U basically _eDraw with the supply current I of instantaneous adjustment, at least for above-mentioned situation and with current regulating signal I _{3_stell}Be designed to, stablize input voltage U in order to allow _eSufficiently high shunting I ₃Flow through and make the transistor in the input voltage regulation device can be with enough degree conduction.In order to reach this purpose, inside (inside of pressurizer 30 here) at the input voltage regulation device, according to another structure of the present invention, the member of the heat energy derivation that is used to dissipate electric energy and will wherein forms thus also is provided, particularly have the semiconductor element of cooling fin etc.Current regulating signal I on the other hand _{3_stell}Also be designed to the shunting I that moment flows in this reduces pressurizer 30 when the power demand in the Operations Analyst circuit 50 becomes big gradually ₃

As show in addition among Fig. 5 that provide, Operations Analyst circuit 50 is at least off and on not only by keeping the first constant effective voltage U under normal operation basically in field apparatus electronic system 20 of the present invention and field apparatus of the present invention _N1Power supply, the first particularly variable effective current I _N1Flow through and by the second effective voltage U that changes according to operation _N2Power supply, the second particularly variable effective current I _N2Flow through.Such advantage is, for the structural group and the circuit of field apparatus electronic system 20 provides instantaneous in fact required electric energy all the time, this structural group and circuit are controlled the normal running of field apparatus electronic system at least and are made field apparatus keep operation, particularly aforesaid at least one microprocessor μ C.In view of the above of the present invention one the structure in provide, aforesaid microprocessor μ C and/or aforesaid signal processor to small part to remain the first constant effective voltage U in the normal running _N1Perhaps operate by the secondary voltage of its derivation.Constructed according to the invention one improves, the first effective voltage U _N1Perhaps by the secondary voltage of its derivation to the operating voltage of small part as at least one A/D converter in the Operations Analyst circuit.Another structure according to the present invention is designed to, and operates member (not only microprocessor μ C also has telecommunication circuit COM) to the small part of the field apparatus electronic system of communicating by letter with aforementioned upper level operation and control unit with maintenance at least here and passes through the first effective voltage U _N1Perhaps by powering with the secondary voltage of its dividing potential drop.

Which electrical power in fact can be provided in operation and depend in aforementioned manner according to externally fed circuit 70 sides by the first effective voltage U _N1The situation of true demand power of the load of power supply, can be for driver element 50B be used in particular for generating drive signal i _ExeIndependent member to small part by the first effective voltage U _N1Perhaps by powering with the secondary voltage of its dividing potential drop, for example this member can be the amplifier in the driver element, and D/A converter and/or signal generator or the like also can in contrast to Figure 12 here.Certainly also demonstrate, in normal running, only the power of the about 30mW of demand has all the time connected up for existing microprocessor μ C and/or A/D converter and their required peripheries, but so at least in the application of the about govern power all the time of 40mW, that is to say the terminal voltage of 12v, the aforementioned components of driver element 50B is merely able to be connected in the first effective voltage U with very little scope _N1Do not damage the high stability of expectation with this.Be designed in addition in structure of the present invention thus, the independent member of driver element 50B only operates in the second effective voltage U especially enduringly _N2Also instead shown the second effective voltage U as Figure 12 _N2Be particularly suitable as the operating voltage of the computing-amplifier in the driver element 50B.Accordingly, the exciting current i of magnet exciting coil _ExeBasically can be by the second effective voltage U _N2Perhaps by powering with the secondary voltage of its dividing potential drop.

For the temporary transient voltage fluctuation of cross-over connection supply power voltage side and/or buffering because the possible moment " overload " of the field apparatus builtin voltage supply that the of short duration rising of internal power demand causes, for example when measuring transducer starts or during the overriding of described long-time memory EEPROM, in the Operations Analyst circuit, provide the capacitive especially memory circuit that is used for temporary transient store electrons energy in addition according to of the present invention improving.Here among the embodiment of Xian Shiing, energy buffer C is as the part of pressurizer 30 and show, so be applied in inner input voltage U in fact all the time _eBut in normal running at least in order to guarantee to avoid effective voltage U _N1Collapse, by the first effective voltage U _N1Certainly to guarantee in the structural group of power supply and the prior design of circuit, equal instantaneous govern power but the electrical power maximum of its maximum conversion equals in the normal running electrical power maximum of I domination electrical power and/or its instantaneous conversion.

In another structure of the present invention, provide the second effective voltage U in normal running in addition _N2Depend on the inside input voltage U of field apparatus electronic system _eThe instantaneous voltage value and adjust.The second effective voltage U alternatively or additionally is provided _N2Depend on terminal voltage U _kThe instantaneous voltage value and adjust this terminal voltage U _kBy the supply power voltage dividing potential drop, and descending at first by the field apparatus electronic system.Adjust inner input voltage U like this _e, for example with this voltage and terminal voltage U _kBetween the pressure reduction that exists in normal running, be held constant at as far as possible on the 1v at least, also shown advantage.So also realized at current regulator IS in addition ₁Perhaps under the situation that the operating temperature of whole flow straightener changes, adjust input voltage U by transmission characteristic separately relatively accurately _eAnd the variation that thereupon occurs, and realized inner input voltage U in simple mode _eThe adjustment of very robust.This is for example adjusted can realize that this amplifier will be by inner input voltage U by the differential amplifier in aforesaid measurement and the regulon 60 _eThe detection voltage of corresponding derivation with by terminal voltage U _kThe detection voltage of corresponding derivation subtracts each other.Alternatively or replenish ground, the second effective voltage U _N2Also depend on three shunting I ₁, I ₂, I ₃In at least one transient current intensity and adjust.For example, the second effective voltage U _N2Can depend on the 3rd shunting I ₃Adjust, considering instantaneous input voltage U _eAfterwards, in fact this current strength represented the excess power of instantaneous existence in the field apparatus electronic system.Specially suitable here as measurement parameter is operation pressurizer and definite the 3rd shunting I ₃The second current regulating signal I _{3_stell}

In order to determine and/or monitor the instantaneous mode of operation of field apparatus electronic system, another is perfect according to of the present invention, the instrument that provides the voltage that will descend in the field apparatus electronic system and/or the electric current that flows in the equipment electronic system at the scene and given particularly adjustable threshold value to compare.Be used for the instrument that voltage and/or electric current compare and for example can constitute the measurement of aforementioned power supply circuits and the integration part of regulon.The one perfect structure according to the present invention, the contrast instrument is designed to, if detect by the second effective voltage U _N2Minimum effective voltage limiting value deficiency, this minimum effective voltage limit is the second effective voltage U _N2The given minimum effective voltage limit, and detect by the 3rd the shunting I ₃Minimum diverter pole limit value deficiency, this minimum diverter pole limit value be the 3rd the shunting I ₃The given minimum shunting limit, then equipment electronic system side generates the warning signal X of the not enough power supply of a warning field apparatus electronic system at least at the scene _{Pwr_fail}For the 3rd shunting I ₃Collection, for example can adopt corresponding in input voltage regulation device 30,60 by shunting I ₃The detection resistance R that flows through ₃, this resistance provides basically and the proportional detection voltage of electric current.According to another structure of the present invention, measurement and regulon 60 are by current regulating signal I _{3_stell}Operation pressurizer 30 like this, if when comparator has warned given maximum effective voltage limiting value by second effective voltage to be exceeded, the 3rd shunting I ₃Especially at this moment just flow, this comparator compares second effective voltage and the reference voltage under at least one.The instrument that for example is used for contrast potential and/or electric current can be simple comparator, and the detection voltage that this comparator will be separately compares with the proportional reference voltage of threshold value separately with affiliated, for example passes through input voltage U _eThe inner reference voltage that generates.

Claims

1. field apparatus electronic system (20) that is used for field apparatus by external power source (70) power supply, wherein external power source (70) provides the particularly supply power voltage (U of one pole _v) and the variable supply current particularly one pole and/or bipolar (I) that drives by this supply power voltage, this field apparatus electronic system (20) comprising:

-current regulator (the IS that flows through by supply current (I) ₁), be used for adjusting and/or the clock of modulation supply current, particularly supply current (I);

-be used to control the built-in function and the analysis circuit (50) of field apparatus; And

-in-line power circuit (40), it is applied in from supply power voltage (U _v) the inner input voltage (U of field apparatus electronic system (20) of dividing potential drop _e), and to built-in function and analysis circuit (50) power supply, this in-line power circuit has;

--the first voltage regulator (UR ₁), it is at least off and on by particularly variable supply current (I) first shunting (I ₁) flow through, this voltage regulator provides the first inner effective voltage (U in the field apparatus electronic system (20) _N1), adjust to this effective voltage substantial constant can be given the first level (U _{N1_soll});

--the second voltage regulator (UR ₂), it is at least off and on by particularly variable supply current (I) second shunting (I ₂) flow through, this voltage regulator provides the second inner effective voltage (U in the field apparatus electronic system (20) _N2), this effective voltage is variable in voltage range that can be given; And

--pressurizer (30), it is at least off and on by particularly variable supply current (I) the 3rd shunting (I ₃) flow through, this pressurizer is used for the inside input voltage (U with field apparatus electronic system (20) _e) adjust and remain to can be given level, particularly variable level in operating process;

-wherein the operation and analysis circuit (50) at least off and on not only by the first particularly variable effective current (I _N1) flow through and by the second particularly variable effective current (I _N2) flow through, wherein first effective current is by the first effective voltage (U _N1) drive, second effective current is by the second effective voltage (U _N2) drive.

2. according to the field apparatus electronic system of aforementioned claim, the inside input voltage (U of field apparatus electronic system wherein _e) depend on terminal voltage (U _k) the instantaneous voltage value and adjust, this terminal voltage is from supply power voltage (U _v) dividing potential drop and initial and descend through the field apparatus electronic system.

3. according to the field apparatus electronic system of claim 1, the second effective voltage (U of field apparatus electronic system wherein _N2) depend on terminal voltage (U _k) the instantaneous voltage value and adjust, this terminal voltage is from supply power voltage (U _v) dividing potential drop and initial and descend through the field apparatus electronic system.

4. according to the field apparatus electronic system of aforementioned claim, the inside input voltage (U of field apparatus electronic system wherein _e) depend on terminal voltage (U _k) the instantaneous voltage value and adjust.

5. according to the field apparatus electronic system of claim 2 or 3, the inside input voltage (U of field apparatus electronic system (20) wherein _e) by pressurizer (30) remain on can be given particularly operation on the variable level, this level is lower than terminal voltage (U _k).

6. according to the field apparatus electronic system of one of aforementioned claim, wherein pass through pressurizer (30) with inner input voltage (U _e) remain on this level, this level can be in operation particularly stagelyly or variable constantly basically.

7. according to the field apparatus electronic system of one of aforementioned claim, the second effective voltage (U wherein _N2), depend on the inside input voltage (U of field apparatus electronic system _e) the instantaneous voltage value and adjust.

8. according to the field apparatus electronic system of one of aforementioned claim, the second effective voltage (U wherein _N2) depend on three the shunting (I ₁, I ₂, I ₃) at least one transient current intensity and adjust.

9. according to the field apparatus electronic system of one of aforementioned claim, the second effective voltage (U wherein _N2) depend on the 3rd the shunting (I ₃) transient current intensity and adjust.

10. according to the field apparatus electronic system of one of aforementioned claim, the second effective voltage (U wherein _N2) depend on second the shunting (I ₂) transient current intensity and the inside input voltage (U of field apparatus electronic system _e) the instantaneous voltage value and adjust.

11. according to the field apparatus electronic system of one of aforementioned claim, wherein Wai Bu power supply (70) provide have variable, the supply power voltage (U of Bo Dong magnitude of voltage particularly _v).

12. according to the field apparatus electronic system of one of aforementioned claim, the supply power voltage (U that provides by external power source (70) wherein _v) drive current intensity variable, the particularly supply current (I) that fluctuates in unpredictable mode basically.

13., wherein in operation and analysis circuit (50), provide the memory circuit that is used for temporary transient storage of electrical energy (C) according to the field apparatus electronic system of one of aforementioned claim.

14. according to the field apparatus electronic system of one of aforementioned claim, wherein pressurizer (30) comprises the member (IS that is mainly used in the dissipation electric energy and derives the heat energy that wherein forms thus ₂), semiconductor element etc. particularly.

15., wherein in operation and analysis circuit (50), provide at least one microprocessor (μ C), wherein the first effective voltage (U according to the field apparatus electronic system of one of aforementioned claim _N1) or by the secondary voltage of its derivation to small part as operating voltage.

16., wherein in operation and analysis circuit (50), provide at least one digital signal processor, wherein the first effective voltage (U according to the field apparatus electronic system of one of aforementioned claim _N1) or by the secondary voltage of its derivation to small part as operating voltage.

17., wherein in operation and analysis circuit (50), provide at least one amplifier, wherein two effective voltage (U according to the field apparatus electronic system of one of aforementioned claim _N1, U _N2) at least one or by the secondary voltage of its derivation to small part as operating voltage.

18., wherein in operation and analysis circuit (50), provide at least one A/D converter, wherein the first effective voltage (U according to the field apparatus electronic system of one of aforementioned claim _N1) or by the secondary voltage of its derivation to small part as operating voltage.

19., wherein in operation and analysis circuit (50), provide at least one D/A-transducer, wherein two effective voltage (U according to the field apparatus electronic system of one of aforementioned claim _N1, U _N2) at least one or by the secondary voltage of its derivation to small part as operating voltage.

20., also provide the decline of voltage in the equipment electronic system (20) at the scene and/or the mobile instrument that compares of electric current in the equipment electronic system (20) at the scene in this external operation and the analysis circuit according to the field apparatus electronic system of one of aforementioned claim.

21. field apparatus electronic system according to one of aforementioned claim, be lower than for given minimum effective voltage limiting value of second effective voltage and the 3rd shunting and be lower than for the given minimum diverter pole limit value of the 3rd shunting if wherein detect second effective voltage in operation and analysis circuit, then operation and analysis circuit generate the alarm signal (X of the deficiency power supply of a warning field apparatus electronic system at least _{Pwr_fail}).

22. according to the field apparatus electronic system of one of aforementioned claim 20 to 21, this field apparatus electronic system also comprises the comparator that detection voltage that at least one will be derived by the 3rd shunting of supply current and affiliated reference voltage compare in addition.

23., comprise one in addition with second effective voltage and reference voltage compares under at least one comparator according to the field apparatus electronic system of one of aforementioned claim 20 to 22.

24. field apparatus electronic system according to one of aforementioned claim, comprise in addition and measuring and regulon (60), be used for detecting and particularly second effective voltage and/or interior particularly the second and/or the 3rd shunting of streaming current of field apparatus electronic system of the interior drop-out voltage of adjustment field apparatus electronic system.

25. field apparatus electronic system according to aforementioned claim 23 and 24, wherein measurement and regulon are controlled pressurizer like this, if make that the comparator of second effective voltage and reference voltage comparison under at least one is signaled second effective voltage have been exceeded for the given maximum effective voltage limiting value of second effective voltage, then the 3rd shunting is flowed.

26. according to the field apparatus electronic system of aforementioned claim 24 or 25, wherein measurement and regulon are according to input voltage (U _e) and/or terminal voltage (U _k) with input voltage (U _e) and terminal voltage (U _k) between the pressure reduction (U that forms _k-U _e) adjust to a given magnitude of voltage that particularly is equal to or greater than 1V.

27., comprise the detection resistance (R that is used to generate basically with the proportional detection voltage of electric current in addition according to the field apparatus electronic system of one of aforementioned claim ₁, R ₂, R ₃).

28. according to the field apparatus electronic system of one of aforementioned claim, this service system only is electrically connected by a unique two-conductor line (2L) with the power supply of outside.

29. field apparatus, be used to measure and/or monitor at least one given physics and/or chemical parameters, particularly import the flow of the medium in conduit and/or the container, density, viscosity, material level, pressure, temperature, PH-value etc., this measuring instrument comprises as the field apparatus electronic system of one of claim 1 to 28 and physics-electronic survey sensor (10) of being connected with the electric coupling of field apparatus electronic system, and this transducer is made a response for the variation of at least one parameter and provided at least one and the corresponding measuring-signal (S of this parameter at least off and on ₁, S ₂), particularly variable signal voltage and/or variable signal code (S ₁, S ₂).

30. according to the field apparatus of aforementioned claim, wherein the operation of field apparatus electronic system and analysis circuit generate a particularly transient measurement value (X of numeral that represents the parameter that will measure and/or will monitor at least at least off and on by at least one measuring-signal _M).

31. field apparatus according to aforementioned claim 29 or 30, wherein measure and analytic unit (60) and the particularly linear flow straightener of the common formation of current regulator, and wherein flow straightener is adjusted supply current according to the measured value of at least one measurement of instantaneous representative and/or monitoring parameter.

32. according to the field apparatus of aforementioned claim 31, wherein supply current is that variable direct current and flow straightener is designed to the amplitude of supply current is modulated on the measured value at least off and on.

33. according to the field apparatus of aforementioned claim 31, wherein supply current is pulse current at least off and on, and wherein flow straightener provides clock pulse for supply current.

34. field apparatus according to aforementioned claim 29 to 33, wherein operation and analysis circuit comprise that at least one is used for the drive circuit of measuring transducer (10) (50B), and second effective voltage or secondary voltage to the small part that derived by this effective voltage are used to operating voltage in this circuit (50B).

35. according to the field apparatus of aforementioned claim, wherein drive circuit comprises operational amplifier at least.

36. according to the field apparatus of aforementioned claim 34 or 35, wherein drive circuit comprises at least one D/A-transducer.

37. according to the field apparatus of one of aforementioned claim 34 to 36, wherein drive circuit comprises that at least one is used to generate the particularly signal generator of numeral of drive signal.

38. according to the field apparatus of one of aforementioned claim 34 to 37, wherein measuring transducer comprises the particularly variable electrical impedance by drive circuitry, particularly has the magnet exciting coil of variable inductance and/or has the measurement electric capacity of variable capacitance.

39. according to the field apparatus of aforementioned claim, wherein electrical impedance is by drive circuitry.

40. according to the field apparatus of aforementioned claim 38 or 39, wherein the electrical impedance of measuring transducer depends at least one measurement and/or monitoring parameter and changes.

41. according to the field apparatus of aforementioned claim, wherein through the signal voltage that descends from the power transformation impedance and/or by the signal code that flows through from the power transformation impedance as measuring-signal.

42. field apparatus according to one of aforementioned claim 29 to 41, wherein operation and analysis circuit comprise at least one A/D converter at least one sensor signal, in this transducer first effective voltage or the secondary effective voltage of deriving by this voltage to small part as operating voltage.

43. field apparatus according to aforementioned claim, wherein operation and analysis circuit comprise what at least one was connected with A/D converter, particularly pass through the microcomputer that microprocessor and/or signal processor constitute, be used for the generation of measured value, wherein first effective voltage is to the operating voltage of small part as microcomputer.

44. according to the field apparatus of one of aforementioned claim 29 to 43, wherein measuring transducer comprises that at least one is used for the measuring tube of boot media (13), it is fit in the conduit, particularly vibration at least off and in operation.

45., wherein disposed one at least and be used to generate the particularly magnet exciting coil of variable magnetic field (26,36) of magnetic field at the measuring transducer place according to the field apparatus of aforementioned claim.

46. according to the field apparatus of aforementioned claim, the exciting current (I that in measuring transducer operation, generates by magnetic field at least off and on of magnet exciting coil (26,36) wherein _Exe) flow through, this exciting current is particularly ambipolar and/or current strength is variable, drives by second effective voltage or by the secondary voltage that this voltage is derived.

47. according to the field apparatus of aforementioned claim, wherein magnet exciting coil (26,36) interacts by magnetic field and movable core (27,37), and wherein field coil and movable core can move relative to each other.

48. field apparatus according to aforementioned claim, wherein at least one measuring tube (13) of measuring transducer is driven by the excitation system that forms by field coil and movable core, vibration at least off and in the measuring transducer operation, this excitation system is the particularly electronic excitation system of motor.

49. according to the field apparatus of aforementioned claim, wherein measuring transducer comprises two measuring tubes that are used for boot media, they are fit into conduit and vibration at least off and in operation.

50. field apparatus according to one of aforementioned claim 29 to 43, wherein measuring transducer is used to detect at least one parameter of the container that medium is housed, material level particularly, and this measuring transducer comprises that at least one stretches into measuring probe container intracavity or that communicate with inner chamber at least for this reason, microwave antenna particularly, the Gouboun-lead, vibration slip into body etc.

51. field apparatus according to one of aforementioned claim 29 to 52, wherein this field apparatus is communicated by letter with peripheral operation and control unit away from field device configurations by data transmission system at least off and on, wherein also provides the telecommunication circuit (COM) of control through the communication of data transmission system in the equipment electronic system at the scene.

52. according to the field apparatus of aforementioned claim, the first effective voltage (U wherein _N1) or the secondary voltage of deriving thus to the operating voltage of small part as telecommunication circuit (COM).

53. according to the field apparatus of one of aforementioned claim 29 to 52, wherein field apparatus electronic system and external power source (70) only are electrically connected by unique two-conductor line (2L) and this field apparatus electronic system (20) at least intermittently at least one measurement of representative of generation and/or the particularly digital transient measurement value (X of monitoring parameter _M) by this unique two-conductor line (2L) be transferred in the power supply (70) externally and/or with analysis circuit that this power supply electric coupling is connected in (80).

54. according to the field apparatus of aforementioned claim, the supply current transient current intensity of wherein particularly adjusting to the value between 4mA and the 20mA has been represented the measured value (X of instantaneous generation _M).

55. field apparatus, be used to adjust at least one given physics and/or chemical parameters, particularly import the flow of the medium in conduit and/or the container, density, viscosity, material level, pressure, temperature, PH-value etc., this measuring instrument comprises the regulating and controlling element as field apparatus electronic system of one of claim 1 to 28 and the electronic-physical that is connected with the electric coupling of field apparatus electronic system, this regulating and controlling element with its to adjusting the influential adjustment action of parameter the variation to the control signal of at least one setting react signal voltage that this control signal is particularly variable and/or variable signal code.